In general, meteorologists do not consider day-to-day forecasts
for more than a week or 10 days ahead to be possible, and the best forecasts
are for five days or less into the future.

Instead of trying to predict the day-to-day weather for
more than a week or 10 days ahead, forecasters produce generalized outlooks
giving the odds of temperatures and precipitation being average, above average
or below average for days, months, or entire seasons.